Farm water supply needs careful management

One good thing about a serious drought is that it makes people in both town and country realise that if it doesn't rain, how very vulnerable we humans are, especially farmers who rely on pastures to make a living. Suddenly people are realising that water is a lot more important than oil – and that it too has a cost. So having an efficient, reliable water supply on the farm is critical.

Aim
To have a water system that delivers potable (safe for humans) water all year round to meet the demands of the farmhouse, the farm dairy and the livestock.

Good signs

• Clean and clear water when poured into a glass and held up to the light. No floating bodies!
• No family health problems, especially diarrhoea in the children.
• No milk penalties in the farm dairy caused by poor water quality.
• Healthy stock drinking the water with relish.
• A water reticulation system that keeps all the troughs full to meet the demands of the stock.
• Hot water pipes that don't corrode.
• No stains under taps.

Bad signs

• Children and adults with regular attacks of diarrhoea.
• Visitors who refuse to drink the water or even tea or coffee made from it.
• Troughs and pipes blocked with sludge.
• Iron (orange-brown) stains on all surfaces where the water runs.
• Orange-brown floating sediment in a glass of water when held up to the light.
• Blue (copper) and black (manganese) stains under taps and in the toilet.
• Water with a rotten smell.
• Stock reluctant to drink from troughs.
• Hard thick deposit inside the kettle or hot water jug.

Problems seen regularly on the farm

Fixing water problems is a major job on a farm, and most of them can be traced back to poor installation and poor maintenance. Here are some common examples:

• No farm map/plan to show where the water pipes were laid, so hours are wasted digging for leaking pipes.
• Wasting time trying to find a leak because its not be where the water is seen coming out of the ground.
• Pumps that are old and have not been serviced so break down at times when it's hot and dry and water demand by the stock is high.
• The water system cannot cope because stock numbers have been increased without the water system being upgraded to meet the extra demand.
• Water pipes are far too small to cope with demand so troughs are regularly emptied and stock are waiting for them to fill to get a drink. Low ranking animals such as heifers never get a drink until night and their milk production suffers as a result.
• Wrong sized pipes so water pressure is lost through friction in the system.
• Water pipes laid on the surface so they get damaged by machinery and the water is heated by the sun making it unpalatable to stock.
• Not enough trough space so all animals can get a full drink. A good example is a trough in a fence line so it is shared between two paddocks.
• Stray voltage on the surface of the trough from a leaking electric fence making stock reluctant to drink.
• Dirty filthy troughs, which the farmer thinks make no different to the stock drinking. It does!
• Valves not protected so they are always getting damaged and water is always leaking.
• High metal (eg iron and manganese) content causing off flavours so stock are reluctant to drink.
• Troughs blocked and the water surface covered with iron algae.
• No backflow prevention in the system so bores become contaminated from troughs and hose suck-back.

Water testing – what you can find out?

It's important to have the farm water tested by a registered laboratory. Here are some of the information you can get:

• pH. This shows how acid or alkali the water is. Acid water (low pH) can be corrosive and can cause problems in the farm dairy by lowering the strength of disinfectants. Alkali water (high pH) causes scale in pipes and hot water cylinders and can cause corrosion in metal pipes and fixtures. pH 7.0 is neutral and domestic drinking water should normally have a pH of 7.0-8.5. Slightly acid water has a tang that some people like.

• Hardness or total dissolved salts. Water with low salts is soft (easy to make a soapy lather) and with high levels of calcium is hard (difficult to make a lather).
• Nitrate. Water high in nitrate can be dangerous to infants and not good for adults either. It's very important that any nitrate doesn't come from any human or animal waste (leaking septic tanks or effluent ponds). This can be checked by a bacterial test.
• Iron and manganese. Clues for iron are brown stains (which are not toxic) on everything the water runs over. Clues for manganese (which can be toxic) are black stains. Both can affect the taste and promote bacterial growth. The stains are most easily seen below dripping taps on a white surface.
• Boron. At high levels this can be toxic to plants.
• Others. The test report will also report on copper, calcium, magnesium, sodium, potassium, zinc chloride and sulphate. High levels of all of these can be toxic and will need treatment.
• Harmful bacteria. The main nasties are E coli, coliforms and faecal coliforms. You don't want these in your domestic water. If they are high, then suspect leaking sewage systems (from bores or wells) or animal faeces in streams/dams. So never put a bore down near an effluent systems. Surface water sources such as streams or dams need an efficient filtration and sterilising system.
• Electrical conductivity (EC). This is an indicator of the total dissolved salts and minerals in the water. High levels can cause scale to build up in pipes and precipitation in tanks and troughs. Very high levels can indicate saline intrusion (sea water getting into the system) especially at coastal sites in dry weather, or geothermal water contamination which can have high arsenic levels.

How to submit a water sample.

Contact the company or laboratory doing the testing to get their full instructions, especially if you intend to send the sample direct to their lab. Follow the instructions to the letter or else you'll waste your money.

For microbiology (bugs)

• Use a leak-proof sterile container. Sterilise it by boiling a glass jar and lid for two minutes and allow it to cool to room temperature before use. For chlorinated water you must use a container form the lab containing a special chemical.
• Don't touch the inside of the sterile container and don't rinse it before taking the sample.
• Send a minimum of 300 ml for testing allowing an air space of 1cm in the lid.
• If from a tap, disinfect the tap by wiping with meths or alcohol. Run the tap for 2-3 minutes and turn off. Flame the tap outlet with a lighter or treat it with meths and flame it off. Run the tap again- slowly, and collect the sample with a 10mm head space in the container.
• From wells or bores, operate the pump for at least 5 minutes before sampling.
• From rivers, lakes or reservoirs, hold the container by the base and plunge it below the surface in the current. If there is no current, push the container forward to fill it.
• Label the sample clearly with your contacts.
• For bacto tests, cool the samples before packaging to below 10°C and deliver to the lab within 6 hours. Cool the samples to 2-5°C for delivery within 24 hours.

Chemistry

Use a plastic bottle and collect at least 500ml, or contact the lab to supply you with containers, chiller bins and instructions. This is usually done with no extra charge. For other tests chill the sample to below 2-6°C to delivery within 24 hours.

Packaging

Make a good job of preparing the chiller bin with plenty of ice cubes. Seal it well and mark it "Urgent" and "Fragile". Remember your contact information!